Device for checking the process results of printing presses



Fil ed Nov. 20, 1952 Y J. F. MONROY EI'AL Feb. 8, 1955 DEVICE FORCHECKING THE PROCESS RESULTS OF PRINTING PRESSES United States Patent fDEVICE-FOR CHECKING THE'PRDCESS RESULTS or rnmrmcrnnssns Johan FrederikMonroy, Amsterdam, and Willem Lenaarts', Haarlem Netherlands, a'ssignorsto "hting Ins 'tuiit'yoor Grafische Techniek 'T. N. 0., Amsterdam,Netherlands,-acorporated liody Application November 20, 1952, Serial No.321,702

Claims priority, application Netherlands November 24, 1951 Claims. (Cl.33-1845) The invention relates to a device for checking the processresults of printing presses.

It is known that a printing press is provided with a rotating cylinderwith an elastic lining, on which cylinder the paper to be printed isplaced, and with a printing plate making forward and backward movements,on which the printing form is mounted, which is appropriately providedwith printing ink. The paper is printed by means of the combinedmovements of the cylinder and the printing plate.

In order to achieve the clean and unblurred printing and to preventundue wear of type it is necessary at the point where the type is incontact with the paper sheet, the velocities of paper and of type shouldbe exactly the same, i. e. that the distance covered by the paper is thesame as the distance covered by the printing form. As a matter of coursethis is unrealizable in actual practice, but a discrepancy frequentlyamounts to 0.5 to 1.0 mm., sometimes even up to 3 mm. Such a discrepancycauses abrasion which is specially substantial at the beginning and atthe end of the printing form. Consequently it is of the utmostimportance to regulate the velocities of the printing form and thecylinder very accurately. This is a very time-consuming work, as itcannot be done at one go, the result being often unsatisfactory, asexplained above. The cause of this is that, since the lining of thepress cylinder is more or less elastic and in order to obtain a properprint a rather considerable pressure must be exerted upon it, the radiusof the cylinder at the point of contact of the sheet of paper and theprinting form is not accurately to be determined, so that it isimpossible to ascertain straight away whether the velocity of the sheetof paper at the point of contact with the printing form indeedcorresponds with that of the printing form, and, if it does not, howgreat the discrepancy is.

The present invention is intended to obviate this drawback and to enablethe press to be regulated quickly and very precisely, by accuratelymeasuring the possible discrepancy between the distance covered by thesheet of paper and that of the form, under conditions as prevailingduring the printing proper. The device according to the invention mainlycomprises instead of the printing form a holder to be mounted on thecarriage, provided with a strip which can easily move over it.

The holder is provided with a device indicating a possible movement ofthe strip, such as for example a dial gauge. The device has a heightexactly corresponding with the height of the printing form, so thatwhen, on moving the carriage, it is pushed under the press cylinderprovided with a sheet of paper, the circumstances prevailing during theprinting proper, are imitated as accurately as possible. If, onprinting, the velocity of the paper at the point of contact should notexactly correspond with that of the printing form, the strip will beslightly shifted in relation to its holder. The knowledge of this shiftenables the mechanic to regulate the printing press quickly and withevery degree of accuracy desired. The invention will be elucidated withthe help of an embodiment as shown on the following drawings, of whichFig. 1 is partly a longitudinal section and partly a side aspect andFig. 2 represents a cross section.

The device consists of a U-shaped holder 1C, provided with a strip 9,which, owing to a conveyor consisting The touching' piril-s of'tlie'dialfgail'g'e ism coma ca'te's every mbvemerit'dt the strip in relationto'the holder; [The teps: are" fastened n ftheho1der by "means of dowels'7 and? screws ,11. .The strip isishii'flin'between pressure spri s 3"the ass st 'whieh'z est 'ag'airist' 'tlie .s'top'si The .sprang w ichiisconnected with s p 1 does not rest on this directly, but on'aiftidj'iistztbl' srW'Z. By screwing in this screw more or less, theneutral position of strip 9 in holder 10 can be adjusted in such a waythat the dial gauge indicates 0. The extremities of cage 6 are providedwith plates 4 which catch the middlemost windings of the respectivesprings 3. The effect of this is that the situation of the conveyor inrelation to the strip and the holder is determined, so that the conveyorassumes the position as shown in Fig. 1, when it is not in operation.Without this provision it could happen that the cage moved in relationto the strip and the holder and that when in operationand consequentlystrip 9 is moved in relation to the holderit came into contact with oneof the stops. Consequently, the conveyor, which is hampered in itsmovements by this contact, will exercise on the strip a friction poweropposite to its movement, as a result of which it is possible that thestrip does no longer follow the movement of the pressure cylinderentirely and the indication of dial gauge 14 becomes incorrect. Theheight of the whole device corresponds closely with the height of theprinting form. In order to check the process results, the device ismounted on the printing plate temporarily replacing the printing form,with its length in the direction of movement of the printing plate.

The press is put into operation and the dial gauge is read to seewhether the printing plate indeed is synchronized with the presscylinder or how great the discrepancy is. If the length of thecontrolling device is smaller than that of the sheet of paper to beprinted, measuring may be done in several stages and the measuringresults may be totalized.

It is also possible to use instead of the dial gauge or simultaneouslywith it a cathode ray oscillograph, by means of which irregularities inthe speed of the printing press, especially at greater velocities, canbe ascertained. In this case the strip should have a slight mass, whichmay be attained, for instance, by making it of an aluminum alloy.

We claim:

1. Device for checking the registry between the type form and thecylinder of a printing press comprising, a bed plate mountable in placeof a type form on the type bed of the press, a follower slide slidablysupported in said bed plate and having its upper surface protrudingbeyond said bed plate to contact said cylinder, and means to indicate arelative displacement of said slide with respect to the bed plate.

2. Device according to claim 1, wherein the follower slide is supportedby a roller bed interposed between said slide and the bed plate andsupported by the bed plate.

3. Device for checking the registry between the type form and thecylinder of a printing press, comprising, a bed plate mountable in placeof a type form on the type bed of the press, a follower slide slidablysupported in said bed plate and having its upper surface protrudingbeyond said bed plate to contact said cylinder, means to indicate arelative displacement of said slide with respect to the bed plate, studsmounted on said bed plate at the ends of said slide, and compressioncoil springs positioned with their axes parallel to the direction of themovement of said slide relative to the bed plate, one end of each springabutting a respective end of said slide and the other end of each springengaging a respective stud to maintain said slide floating between itsextreme positions with respect to the bed plate.

4. Device according to claim 3 at least one of the studs beingadjustable to vary the compression of the springs.

5. Device for checking the registry between the type form and thecylinder of a printing press, comprising, a bed plate mountable in placeof a type form on the type bed of the press, a follower slide slidablysupported in said bed plate and having its upper surface protrudingbeyond said bed plate to contact said cylinder, means to indicate arelative displacement of said slide with respect to the bed plate, studsmounted to said bed plate at the ends of said slide, and compressioncoil springs positioned with their axes parallel to the direction of themovement of said slide relative to the bed plate, one end of each springabutting a respective end of said slide and the other end of each springengaging a respective stud to maintain said slide floating between itsextreme positions with respect to the bed plate, an anti-frictionbearing interposed between said follower slide and said bed plate andcomprising solids of revolution and a cage, said cage resting on saidplate and provided with slots, said 4 solids being located in saidslots, at least one end of said cage being provided with means toconnect said cage to the middle-most winding of the adjacent spring.

References Cited in the file of this patent UNITED STATES PATENTS359,402 Pafi Mar. 15, 1887 1,973,363 Wood Sept. 11, 1934 2,114,946Trotter Apr. 19, 1938 2,372,428 Johnson Mar. 27, 1945 2,497,800 RootFeb. 14, 1950 2,593,713 Willett Apr. 22, 1952 2,636,278 Krause Apr. 28,1953

